ECOLOGY Section 2.1 Summary pages What affects the environment also affects you. Understanding what affects the environment is important because it is where you live. Sharing the World Section 2.1 Summary pages The branch of biology that developed from natural history is called ecology. Ecology is the study of interactions that take place between organisms and their environment. What is ecology? Section 2.1 Summary pages The nonliving parts of an organisms environment are the abiotic factors. Examples of abiotic factors include air currents, temperature, moisture, light, and soil. The nonliving environment: Abiotic factors Section 2.1 Summary pages The nonliving environment: Abiotic factors The nonliving environment: Abiotic factors This graph shows how the plants glucose (food) production is affected by temperature Food Production in Salt Bush Temperature (C) Food production (mg of glucose/hr) Section 2.1 Summary pages The living environment: Biotic factors A key consideration of ecology is that living organisms affect other living organisms. All the living organisms that inhabit an environment are called biotic factors. All organisms depend on others directly or indirectly for food, shelter, reproduction or protection. Section 2.1 Summary pages Organism An individual living thing that is made of cells, uses energy, reproduces, responds, grows, and develops. Section 2.1 Summary pages A population is a group of organisms, all of the same species, which interbreed and live in the same area at the same time. Section 2.1 Summary pages A biological community is made up of interacting populations in a certain area at a certain time. Section 2.1 Summary pages Ecosystem Populations of plants and animals that interact with each other in a given area and with the abiotic components of that area. Section 2.1 Summary pages The biosphere is the portion of Earth that supports living things. It extends from high in the atmosphere to the bottom of the oceans. The Biosphere Section 2.1 Summary pages Biotic and abiotic factors form ecosystems Terrestial ecosystems are those located on land. Table 2.1 Examples of Ecosystems Terrestrial Ecosystems Forest Old farm field Meadow Yard Garden plot Empty lot Compost heap Volcano site Rotting log Aquatic Ecosystems Freshwater Pond Lake Stream Estuary Salt water (marine) Ocean Estuary Aquarium Other Sites for Ecosystems Human body Skin Intestine Mouth Buildings Mold in walls, floors, or basement Ventilation systems Bathrooms Food Any moldy food Refrigerator Aquatic ecosystems occur in both fresh- and saltwater forms. Section 2.1 Summary pages Organisms in Ecosystems A habitat is the place where an organism lives out its life. Section 2.1 Summary pages Organisms in Ecosystems Habitats can change, and even disappear. Habitats can change due to both natural and human causes. Section 2.1 Summary pages Niche Although several species may share a habitat, the food, shelter, and other essential resources of that habitat are often used in different ways. A niche is the role or position a species has in its environment how it meets its specific needs for food and shelter, how and where it survives, and where it reproduces in its environment. Section 2.1 Summary pages Niche A species niche, therefore, includes all its interactions with the biotic and abiotic parts of its habitat. It is thought that two species cant exist for long in the same community if their niches are the same. HABITAT OR NICHE ??? P. means Parmecium which is a one-celled protist that lives in ponds and other freshwater bodies of water. Graphs showing competition between two species of Paramecium. Since each population alone prospers (FIRST two graphs), when they are in a competition situation one species will win, the other will lose (THIS graph). Images from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com), used with permission..www.sinauer.comwww.whfreeman.com It is thought that two species cant exist for long in the same community if their niches are the same. One will compete better than the other and survive. Section 2.1 Summary pages Symbiosis The relationship in which there is a close and permanent association between organisms of different species is called symbiosis. Symbiosis means living together. Three kinds of symbiosis are recognized: mutualism, commensalism, and parasitism. Section 2.1 Summary pages A symbiotic relationship in which both species benefit is called mutualism. Section 2.1 Summary pages Commensalism is a symbiotic relationship in which one species benefits and the other species is neither harmed nor benefited. Section 2.1 Summary pages Parasitism Some interactions are harmful to one species, yet beneficial to another. A symbiotic relationship in which a member of one species derives benefit at the expense of another species (the host) is called parasitism. Section 2.1 Summary pages Parasitism Parasites have evolved in such a way that they harm, but usually do not kill the host species. Are these two playing? If not, then what type relationship is this ??? Is it a relationship???